I've done this with all my cars for years, and I'm sure it has helped a lot. Keeping the battery charged is important, but you can't rely on the alternator to get that done. I use a Battery Tender and a SmartShot from Yuasa. They have a cable that connects to the battery and remains under the hood. To charge the battery, you connect the charger to the battery with the cable. You can't plug it in the wrong way, and you can connect/disconnect anything at any time.

These are "smart chargers," and they apply the right amount of current at the right time. You can keep it connected for months with no damage to the battery.

When I connected the charger yesterday afternoon, it took till this morning for the battery to have a full charge.


Robot Check

 

These are great for cars that sit for periods of time, have a high current draw, or both. Have you seen the external magnetic connector? It basically self aligns and connects magnetically. Easy connect and disconnect, and even great for those people who forget it's attached and drive off

 

No, I havent seen that.

 

Battery Charger Mag Hookup

Shown on a Corvette, neat idea though...

 

Are you using the "Battery Tender" cable only or do you have the "Battery Tender" charger as well as the "Smart Shot" charger ... if so what is the difference between the chargers?

 

I think finding a difference would be splitting hairs. They are both smart chargers that supply a large charge, a lower charge, and then a float charge. I like the connectors on the charger and the battery - very fast and easy to connect/disconnect.

 

SilverEX15 is correct, both are multistage chargers, except one has more amperage capacity than the other. I prefer an IOTA engineering DLS series charger. Its a charger and a well regulated 12 volt power supply. It comes in 15 amps all the way to 90 amps @ 12 volts. Its not a dumb charger at constant current. It has float, absorption, bulk, and equalization stages.

 

I don't see the point of a battery tender for a vehicle that is regularly driven. If the charging system can't replenish the battery within a mile or two then there is something seriously wrong with it.

One danger of using a tender is that it might allow a weak battery to start the car every day at home, but then if you take it on a trip and end up somewhere where you cannot charge the battery it might leave you stranded. The battery lasts longer, but fails away from home.

 

I have used these chargers for over ten years, and I have never found any battery that did not need a lengthy charge. Maybe I shouldn't say need, but the charger takes a while to be satisfied that the battery has a complete charge.

If the battery charger never indicates a full charge, then the battery is bad - doesn't hold a charge. I've had that happen, too.

 

Been driving cars for over 40 years. Never used or needed a battery tender. Never had a battery fail to start a car without a reason (lights left on, failed charging system, etc or battery at the end of it's life). To each his own though

 

If I were designing a "battery tender" I would set the float voltage to be a few tenths of a volts above the normal no-load voltage of the battery. I would also set the charging current to be very low in that range, both to prevent damage to the battery and also to give the the person who installed it the impression that the battery tender is actually doing something useful because it indicates that it was charging for a long time before getting to the set float voltage.

 

Now I know the trunk light turns off on its own after about 10-15 minutes, but I found out last night while at the drive in movies, the car shuts off after being on for about an hour. This was with the engine start stop pushed once so it says Power is On. I guess FYI the car will shut off on its own after some time.

Still, it doesn't mean we shouldn't check the battery life. These battery tenders seem to be good investments.

 

I just bought the "Battery Tender Plus" and a spare quick-connect cable for my truck. The FIT is my second vehicle and probably won't be used much once it begins to snow: I'll be driving my 4WD truck. In the mean time my truck is sitting in the garage and driven once a week tops. This seemed an inexpensive tool for piece of mind ... plus this forum has prompted me to purchase quite a few things I never would have bought if I hadn't read about them here.

I like the convenience of the quick disconnect cables. They look like they were factory installed and have dust caps to protect the contacts.

TIP: a layer of petroleum jelly on the contacts (and battery terminals) will keep them clean for years ... did this on my ocean-boat batteries to defray some of the seasonal maintenance, worked excellent!

 

That's one of the purposes of a forum.